Is this a Proto 2 or 3 engine ?
Does this engine already exist in the remote on the inactive list ? You could be dealing with a dead battery if it’s a Proto 2. You can charge or replace the battery. Delete the engine and it should re add.
Or is this engine new to the layout ? Is it coming up silent ? It could be an issue with a bad track signal not being able to find the engine. Test the section you are placing the engine on with a working engine and perform a track signal test. Or you could set up a temporary programming track.